Bryan, I can recommend the NHRC-4 controller for the service you want to
implement. I'm not sure but I think the ICS-Basic you mentioned is a repeater
controller that does not have the second port to control your link.
I have built up 3 of the NHRC-4 controller kits and used them in two port
service where the main port controls a repeater and the second port controls a
simplex radio on another band and can recommend them for this type of service.
They were easy to build, and the later control system is very easy to set up
using the zone type of control groupings. I ordered the remaining parts from
Digikey for my controllers, and the suggested part numbers in the manual work
out fine. With a well stocked junk box, you may have a lot of the parts. I
did not have to order a single resistor or bypass capicator for my kits.
You could probably get started using the existing VHF radio, and if it proves
to have too much coverage you could change the radio. When working with hand
held radios you may find that the extra power is useful even when the handhelds
can't talk back to the simplex port. Being able to copy EMCOMMS even when you
can't talk back can be of some use.
Finding the correct interface for the radios to the controller can be a pain,
but can usually be accomplished. The NHRC controller can handle receive audio
that is already equalized, or can equalize the audio from the receiver
discriminator inside the controller. Same with the receive audio from the VHF
simplex radio.
73 - Jim W5ZIT
--- On Sat, 11/29/08, bkcarter33 <[EMAIL PROTECTED]> wrote:
From: bkcarter33 <[EMAIL PROTECTED]>
Subject: [Repeater-Builder] How to set up a basic crossband repeater system in
Public Service
To: Repeater-Builder@yahoogroups.com
Date: Saturday, November 29, 2008, 12:03 AM
My local Community Emergency Response Team (CERT) has recently
obtained a UHF repeater (ICOM CY-F221S).
It has two ICOM F221S radios linked together in a nice rack mount box.
It has also been set up with a remote mic and speaker off of the
outputs on the chassis back panel.
The CERT group is licensed for the UHF repeater frequencies and they
are in the public service band. They also have a simplex VHF
frequency in the PS band (old police frequency) licensed.
They have a number of Motorola HT radios (CP200) that operate on the
simplex VHF frequency.
They are looking at obtaining additional UHF HT radios in the future
but would like to be able to use the equipment they have if they can
get it to work together.
I am familiar enough with electronics to be able to follow
directions, but not enough to design anything beyond a basic switch
box.
I am a network engineer professionally so I am pretty well versed in
those areas, and understand logic control pretty well.
I am a technician class ham, but don't know a lot about RF as I have
not had that much experience in it.
I would like to accomplish the following and would love to receive
some guidance from someone who has the knowledge to instruct me:
I would like to set up a cross band link for them from the UHF
repeater, to a VHF radio:
This would allow someone on the UHF side to transmit to the repeater,
and also cross-band repeat to the VHF side.
The VHF side would be able to transmit on the VHF simplex frequency
to the cross band side, and it would repeat onto the UHF side.
I realize that this would NOT provide VHF to VHF repeating, and that
is okay.
I want to provide a way that the cross band link can be enabled and
disabled by remote DTMF tones so that the bands can be separated when
desired.
I already have an old Motorola Spectra police radio operating on the
VHF side at the site, and it has a dedicated antenna. It puts out
110W which is way too much for what we need.
I was thinking about getting an ICOM F121S radio, Astron power
supply, and ICS basic controller board.
Using the existing VHF antenna, I would hook up the new ICOM (50
watts or less).
Now I just need to tie the ICOM repeater, controller, and new radio
together into a cross band system of sorts.
Am I on the right track? I need some general guidance that can tell
me, try this, this, and this. Here is what equipment you could use,
and here is how you could tie it together. I have the schematics for
the repeater available to me.
If I don't want to spend the money for a new ICOM F121S radio, then
what else could I connect easily that I can program and would be able
to get at a reasonable price.
This is all being done as volunteer service so inexpensive is best,
but I want to avoid "cheap" equipment.
Thanks for any help you could provide me,
73
Bryan Carter
KE7GVJ
Kaysville CERT Administration
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